How do I make objects transparent in edit mode in 2.8
You could Toggle X-Ray, located in the 3D Viewport Header. Or click the little downward pointing &quot;&gt;&quot; icon to open the Viewport Shading panel and check the box next to X-ray. Or press Alt + Z.

As stated by moonboots, in the Viewport Shading panel you can also change the amount of transparency.
(moonboots comment was quite adequate but i though they made a mistake, while actualy i had my keybindings messed up: apologies)